The present invention relates principally to a device for occlusion adapted to be introduced into a vessel.
It also relates to an apparatus for emplacement of a vascular occlusion device as well as a process for use of such a device.
The invention will find its application in the field of the production and use of occlusive prostheses for any type of vessel in the human or animal body.
Vascular occlusion systems exist already but are not entirely satisfactory.
There is known from U.S. Pat. No. 5,382,261 a method and apparatus to occlude vessels.
According to this document, a permanent occlusion of a vessel is possible for a person, by use of a flexible obstruction element fixed to at least one radially expansible metallic portion, generally of tubular shape, the flexible obduration element having a substantially tubular longitudinal configuration.
According to this document, the occlusion element is a type of plug of tubular shape connected to a securement member in a vessel in the form of a stent, comprised by an expansible metallic armature.
In this prior art, the degree of occlusion is not adjustable.
It will generally be total and this in a permanent manner.
It will be noted moreover that the securement of the occlusion device in the vessel takes place from a single side of the obduration element.
The forces thereon are thus concentrated when the blood pressure is applied to the interior of the occlusive system.
Other occlusive systems have been proposed, particularly that disclosed in EP0 947 168.
There is there disclosed a coated self-expansible vascular occlusion device which comprises an element in the form of a woven metallic filament comprising at least two axially spaced securement elements and fixed to the woven metallic filament.
A thin film covers at least half the device.
The woven element proposed is adapted to expand radially when it is freed within the blood vessel so as to close the blood vessel.
Upon its release, it immediately and completely produces occlusion of the vessel.
Again, this occlusion system serves to occlude the vessel totally and permanently.
Its structure is moreover complicated and has a substantial cost of production.
Moreover, the blood flow is oriented toward the periphery of the vessel, at the level of the connection of the woven element with internal walls of this vessel.
As a result, important forces arise because of the blood pressure which is applied.
To obtain effective sealing, it is thus necessary to provide a high expansive force on the woven element against the internal wall of the vessel.
There is also known from the document DE-C-19 801 076 an expansible member for implantation in a vessel. According to this document, the member comprises two zones 16, 18 adapted to be relatively fixed to the wall of the vessel to hold the member. An intermediate hollow portion is moreover present to ensure the passage of the flow of blood. This device constitutes essentially an accessory for carrying out surgical procedures adapted to short-circuit a vessel. It is not an occlusion device, and no deformation by torsion is present.